"""
Integration tests for streaming download functionality.

Tests cover:
- HTTP Range requests (partial downloads, resume)
- Conditional requests (If-None-Match, If-Modified-Since)
- Caching headers (Cache-Control, Last-Modified, Accept-Ranges)
- Large file streaming
- Download modes (proxy, redirect, presigned)
"""

import pytest
import io
import time
from email.utils import formatdate
from tests.factories import (
    compute_sha256,
    upload_test_file,
)
from tests.conftest import (
    SIZE_1KB,
    SIZE_100KB,
    SIZE_1MB,
)


class TestRangeRequests:
    """Tests for HTTP Range request support (partial downloads)."""

    @pytest.mark.integration
    def test_range_request_first_bytes(self, integration_client, test_package):
        """Test range request for first N bytes."""
        project, package = test_package
        content = b"0123456789" * 100  # 1000 bytes
        upload_test_file(integration_client, project, package, content, version="range-test")

        # Request first 10 bytes
        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/range-test",
            params={"mode": "proxy"},
            headers={"Range": "bytes=0-9"},
        )
        assert response.status_code == 206  # Partial Content
        assert response.content == b"0123456789"
        assert "Content-Range" in response.headers
        assert response.headers["Content-Range"].startswith("bytes 0-9/")

    @pytest.mark.integration
    def test_range_request_middle_bytes(self, integration_client, test_package):
        """Test range request for bytes in the middle."""
        project, package = test_package
        content = b"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
        upload_test_file(integration_client, project, package, content, version="range-mid")

        # Request bytes 10-19 (KLMNOPQRST)
        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/range-mid",
            params={"mode": "proxy"},
            headers={"Range": "bytes=10-19"},
        )
        assert response.status_code == 206
        assert response.content == b"KLMNOPQRST"

    @pytest.mark.integration
    def test_range_request_suffix_bytes(self, integration_client, test_package):
        """Test range request for last N bytes (suffix range)."""
        project, package = test_package
        content = b"0123456789ABCDEF"  # 16 bytes
        upload_test_file(integration_client, project, package, content, version="range-suffix")

        # Request last 4 bytes
        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/range-suffix",
            params={"mode": "proxy"},
            headers={"Range": "bytes=-4"},
        )
        assert response.status_code == 206
        assert response.content == b"CDEF"

    @pytest.mark.integration
    def test_range_request_open_ended(self, integration_client, test_package):
        """Test range request from offset to end."""
        project, package = test_package
        content = b"0123456789"
        upload_test_file(integration_client, project, package, content, version="range-open")

        # Request from byte 5 to end
        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/range-open",
            params={"mode": "proxy"},
            headers={"Range": "bytes=5-"},
        )
        assert response.status_code == 206
        assert response.content == b"56789"

    @pytest.mark.integration
    def test_range_request_includes_accept_ranges_header(
        self, integration_client, test_package
    ):
        """Test that range requests include Accept-Ranges header."""
        project, package = test_package
        content = b"test content"
        upload_test_file(integration_client, project, package, content, version="accept-ranges")

        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/accept-ranges",
            params={"mode": "proxy"},
            headers={"Range": "bytes=0-4"},
        )
        assert response.status_code == 206
        assert response.headers.get("Accept-Ranges") == "bytes"

    @pytest.mark.integration
    def test_full_download_advertises_accept_ranges(
        self, integration_client, test_package
    ):
        """Test that full downloads advertise range support."""
        project, package = test_package
        content = b"test content"
        upload_test_file(integration_client, project, package, content, version="full-accept")

        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/full-accept",
            params={"mode": "proxy"},
        )
        assert response.status_code == 200
        assert response.headers.get("Accept-Ranges") == "bytes"


class TestConditionalRequests:
    """Tests for conditional request handling (304 Not Modified)."""

    @pytest.mark.integration
    def test_if_none_match_returns_304(self, integration_client, test_package):
        """Test If-None-Match with matching ETag returns 304."""
        project, package = test_package
        content = b"conditional request test content"
        expected_hash = compute_sha256(content)
        upload_test_file(integration_client, project, package, content, version="cond-etag")

        # Request with matching ETag
        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/cond-etag",
            params={"mode": "proxy"},
            headers={"If-None-Match": f'"{expected_hash}"'},
        )
        assert response.status_code == 304
        assert response.content == b""  # No body for 304

    @pytest.mark.integration
    def test_if_none_match_without_quotes(self, integration_client, test_package):
        """Test If-None-Match works with or without quotes."""
        project, package = test_package
        content = b"etag no quotes test"
        expected_hash = compute_sha256(content)
        upload_test_file(integration_client, project, package, content, version="cond-noquote")

        # Request with ETag without quotes
        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/cond-noquote",
            params={"mode": "proxy"},
            headers={"If-None-Match": expected_hash},
        )
        assert response.status_code == 304

    @pytest.mark.integration
    def test_if_none_match_mismatch_returns_200(self, integration_client, test_package):
        """Test If-None-Match with non-matching ETag returns 200."""
        project, package = test_package
        content = b"etag mismatch test"
        upload_test_file(integration_client, project, package, content, version="cond-mismatch")

        # Request with different ETag
        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/cond-mismatch",
            params={"mode": "proxy"},
            headers={"If-None-Match": '"different-etag-value"'},
        )
        assert response.status_code == 200
        assert response.content == content

    @pytest.mark.integration
    def test_if_modified_since_returns_304(self, integration_client, test_package):
        """Test If-Modified-Since with future date returns 304."""
        project, package = test_package
        content = b"modified since test"
        upload_test_file(integration_client, project, package, content, version="cond-modified")

        # Request with future date (artifact was definitely created before this)
        future_date = formatdate(time.time() + 86400, usegmt=True)  # Tomorrow
        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/cond-modified",
            params={"mode": "proxy"},
            headers={"If-Modified-Since": future_date},
        )
        assert response.status_code == 304

    @pytest.mark.integration
    def test_if_modified_since_old_date_returns_200(
        self, integration_client, test_package
    ):
        """Test If-Modified-Since with old date returns 200."""
        project, package = test_package
        content = b"old date test"
        upload_test_file(integration_client, project, package, content, version="cond-old")

        # Request with old date (2020-01-01)
        old_date = "Wed, 01 Jan 2020 00:00:00 GMT"
        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/cond-old",
            params={"mode": "proxy"},
            headers={"If-Modified-Since": old_date},
        )
        assert response.status_code == 200
        assert response.content == content

    @pytest.mark.integration
    def test_304_includes_etag(self, integration_client, test_package):
        """Test 304 response includes ETag header."""
        project, package = test_package
        content = b"304 etag test"
        expected_hash = compute_sha256(content)
        upload_test_file(integration_client, project, package, content, version="304-etag")

        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/304-etag",
            params={"mode": "proxy"},
            headers={"If-None-Match": f'"{expected_hash}"'},
        )
        assert response.status_code == 304
        assert response.headers.get("ETag") == f'"{expected_hash}"'

    @pytest.mark.integration
    def test_304_includes_cache_control(self, integration_client, test_package):
        """Test 304 response includes Cache-Control header."""
        project, package = test_package
        content = b"304 cache test"
        expected_hash = compute_sha256(content)
        upload_test_file(integration_client, project, package, content, version="304-cache")

        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/304-cache",
            params={"mode": "proxy"},
            headers={"If-None-Match": f'"{expected_hash}"'},
        )
        assert response.status_code == 304
        assert "immutable" in response.headers.get("Cache-Control", "")


class TestCachingHeaders:
    """Tests for caching headers on download responses."""

    @pytest.mark.integration
    def test_download_includes_cache_control(self, integration_client, test_package):
        """Test download response includes Cache-Control header."""
        project, package = test_package
        content = b"cache control test"
        upload_test_file(integration_client, project, package, content, version="cache-ctl")

        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/cache-ctl",
            params={"mode": "proxy"},
        )
        assert response.status_code == 200
        cache_control = response.headers.get("Cache-Control", "")
        assert "public" in cache_control
        assert "immutable" in cache_control
        assert "max-age" in cache_control

    @pytest.mark.integration
    def test_download_includes_last_modified(self, integration_client, test_package):
        """Test download response includes Last-Modified header."""
        project, package = test_package
        content = b"last modified test"
        upload_test_file(integration_client, project, package, content, version="last-mod")

        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/last-mod",
            params={"mode": "proxy"},
        )
        assert response.status_code == 200
        assert "Last-Modified" in response.headers
        # Should be in RFC 7231 format
        last_modified = response.headers["Last-Modified"]
        assert "GMT" in last_modified

    @pytest.mark.integration
    def test_download_includes_etag(self, integration_client, test_package):
        """Test download response includes ETag header."""
        project, package = test_package
        content = b"etag header test"
        expected_hash = compute_sha256(content)
        upload_test_file(integration_client, project, package, content, version="etag-hdr")

        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/etag-hdr",
            params={"mode": "proxy"},
        )
        assert response.status_code == 200
        assert response.headers.get("ETag") == f'"{expected_hash}"'


class TestDownloadResume:
    """Tests for download resume functionality using range requests."""

    @pytest.mark.integration
    def test_resume_download_after_partial(self, integration_client, test_package):
        """Test resuming download from where it left off."""
        project, package = test_package
        content = b"ABCDEFGHIJ" * 100  # 1000 bytes
        upload_test_file(integration_client, project, package, content, version="resume-test")

        # Simulate partial download (first 500 bytes)
        response1 = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/resume-test",
            params={"mode": "proxy"},
            headers={"Range": "bytes=0-499"},
        )
        assert response1.status_code == 206
        first_half = response1.content
        assert len(first_half) == 500

        # Resume from byte 500
        response2 = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/resume-test",
            params={"mode": "proxy"},
            headers={"Range": "bytes=500-"},
        )
        assert response2.status_code == 206
        second_half = response2.content
        assert len(second_half) == 500

        # Combine and verify
        combined = first_half + second_half
        assert combined == content

    @pytest.mark.integration
    def test_resume_with_etag_verification(self, integration_client, test_package):
        """Test that resumed download can verify content hasn't changed."""
        project, package = test_package
        content = b"resume etag verification test content"
        expected_hash = compute_sha256(content)
        upload_test_file(integration_client, project, package, content, version="resume-etag")

        # Get ETag from first request
        response1 = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/resume-etag",
            params={"mode": "proxy"},
            headers={"Range": "bytes=0-9"},
        )
        assert response1.status_code == 206
        etag = response1.headers.get("ETag")
        assert etag == f'"{expected_hash}"'

        # Resume with If-Match to ensure content hasn't changed
        # (Note: If-Match would fail and return 412 if content changed)
        response2 = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/resume-etag",
            params={"mode": "proxy"},
            headers={"Range": "bytes=10-"},
        )
        assert response2.status_code == 206
        # ETag should be the same
        assert response2.headers.get("ETag") == etag


class TestLargeFileStreaming:
    """Tests for streaming large files."""

    @pytest.mark.integration
    def test_stream_1mb_file(self, integration_client, test_package, sized_content):
        """Test streaming a 1MB file."""
        project, package = test_package
        content, expected_hash = sized_content(SIZE_1MB, seed=500)

        upload_test_file(integration_client, project, package, content, version="stream-1mb")

        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/stream-1mb",
            params={"mode": "proxy"},
        )
        assert response.status_code == 200
        assert len(response.content) == SIZE_1MB
        assert compute_sha256(response.content) == expected_hash

    @pytest.mark.integration
    def test_stream_large_file_has_correct_headers(
        self, integration_client, test_package, sized_content
    ):
        """Test that large file streaming has correct headers."""
        project, package = test_package
        content, expected_hash = sized_content(SIZE_100KB, seed=501)

        upload_test_file(integration_client, project, package, content, version="stream-hdr")

        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/stream-hdr",
            params={"mode": "proxy"},
        )
        assert response.status_code == 200
        assert int(response.headers.get("Content-Length", 0)) == SIZE_100KB
        assert response.headers.get("X-Checksum-SHA256") == expected_hash
        assert response.headers.get("Accept-Ranges") == "bytes"

    @pytest.mark.integration
    def test_range_request_on_large_file(
        self, integration_client, test_package, sized_content
    ):
        """Test range request on a larger file."""
        project, package = test_package
        content, _ = sized_content(SIZE_100KB, seed=502)

        upload_test_file(integration_client, project, package, content, version="range-large")

        # Request a slice from the middle
        start = 50000
        end = 50999
        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/range-large",
            params={"mode": "proxy"},
            headers={"Range": f"bytes={start}-{end}"},
        )
        assert response.status_code == 206
        assert len(response.content) == 1000
        assert response.content == content[start : end + 1]


class TestDownloadModes:
    """Tests for different download modes."""

    @pytest.mark.integration
    def test_proxy_mode_streams_content(self, integration_client, test_package):
        """Test proxy mode streams content through backend."""
        project, package = test_package
        content = b"proxy mode test content"
        upload_test_file(integration_client, project, package, content, version="mode-proxy")

        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/mode-proxy",
            params={"mode": "proxy"},
        )
        assert response.status_code == 200
        assert response.content == content

    @pytest.mark.integration
    def test_presigned_mode_returns_url(self, integration_client, test_package):
        """Test presigned mode returns JSON with URL."""
        project, package = test_package
        content = b"presigned mode test"
        upload_test_file(integration_client, project, package, content, version="mode-presign")

        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/mode-presign",
            params={"mode": "presigned"},
        )
        assert response.status_code == 200
        data = response.json()
        assert "url" in data
        assert "expires_at" in data
        assert data["url"].startswith("http")

    @pytest.mark.integration
    def test_redirect_mode_returns_302(self, integration_client, test_package):
        """Test redirect mode returns 302 to presigned URL."""
        project, package = test_package
        content = b"redirect mode test"
        upload_test_file(integration_client, project, package, content, version="mode-redir")

        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/mode-redir",
            params={"mode": "redirect"},
            follow_redirects=False,
        )
        assert response.status_code == 302
        assert "Location" in response.headers


class TestIntegrityDuringStreaming:
    """Tests for data integrity during streaming downloads."""

    @pytest.mark.integration
    def test_checksum_header_matches_content(self, integration_client, test_package):
        """Test X-Checksum-SHA256 header matches actual downloaded content."""
        project, package = test_package
        content = b"integrity check content"
        expected_hash = compute_sha256(content)
        upload_test_file(integration_client, project, package, content, version="integrity")

        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/integrity",
            params={"mode": "proxy"},
        )
        assert response.status_code == 200

        header_hash = response.headers.get("X-Checksum-SHA256")
        actual_hash = compute_sha256(response.content)

        assert header_hash == expected_hash
        assert actual_hash == expected_hash
        assert header_hash == actual_hash

    @pytest.mark.integration
    def test_etag_matches_content_hash(self, integration_client, test_package):
        """Test ETag header matches content hash."""
        project, package = test_package
        content = b"etag integrity test"
        expected_hash = compute_sha256(content)
        upload_test_file(integration_client, project, package, content, version="etag-int")

        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/etag-int",
            params={"mode": "proxy"},
        )
        assert response.status_code == 200

        etag = response.headers.get("ETag", "").strip('"')
        actual_hash = compute_sha256(response.content)

        assert etag == expected_hash
        assert actual_hash == expected_hash

    @pytest.mark.integration
    def test_digest_header_present(self, integration_client, test_package):
        """Test Digest header is present in RFC 3230 format."""
        project, package = test_package
        content = b"digest header test"
        upload_test_file(integration_client, project, package, content, version="digest")

        response = integration_client.get(
            f"/api/v1/project/{project}/{package}/+/digest",
            params={"mode": "proxy"},
        )
        assert response.status_code == 200
        assert "Digest" in response.headers
        assert response.headers["Digest"].startswith("sha-256=")